This invention relates to surgical fastening apparatus, and more particularly to apparatus for applying surgical fasteners comprising two interlocking parts.
Surgical fasteners have been developed which comprise a fastener part having one or more prongs and a retainer part having a corresponding number of apertures for respectively receiving and engaging the ends of the prongs of the fastener part (see, for example, Noiles U.S. Pat No. 4,060,089). Both parts of the fastener are typically made of a plastic or plastic-like material which may be biologically absorbable. In use, the fastener and retainer parts are respectively positioned on opposite sides of the tissue to be fastened. The fastener part is then driven toward the tissue so that the prongs pass through the tissue and interlock with the retainer part. The retainer part prevents the prongs from being withdrawn from the tissue.
In applying surgical fasteners of this type it is important for the retainer part to be held securely prior to engaging the fastener part. This is required to prevent the retainer part from becoming loose and possibly lost in the operating site and to assure that each fastener part mates with a retainer part to provide the intended surgical fastener. Once the fastener and retainer parts have interlocked, however, it is equally important for the structure which supports the retainer part to readily release the retainer part so that the fastened tissue can be easily removed from the fastener applying apparatus. It may also be desirable to provide the operator of the apparatus with an indication as to when the two parts of the fastener have interlocked so that the operator knows when the fastening procedure is complete.
In view of the foregoing, it is an object of this invention to improve and simplify apparatus for applying two-part surgical fasteners of the type described above.
It is a more particular object of this invention to provide apparatus for applying two-part surgical fasteners of the type described above in which the retainer part is held firmly in the apparatus until the two parts of the fastener are joined, at which time an indication is produced that the fastener parts have interlocked and the retainer parts are released from the apparatus.